SMOKE-CONCENTRATION DETECTING APPARATUS FOR INTERNAL COMBUSTION ENGINE

摘要

PURPOSE:To ensure the scavenging of smoke sensor and to make it possible to detect the concentration of smoke in high accuracy by providing the new air intake port and the exhaust gas injecting port for a selector valve at a place where pressure is higher than a gas injecting port. CONSTITUTION:One end of a smoke-concentration detecting path 50 is connected to an air intake pipe 18 on the upstream side from the connecting part of an EGR path 24. A numeral 53 indicates a gas introducing port. A smoke sensor 52 is provided in the smoke-concentration detecting path 50. A fresh-air intake port 54-1 is connected to an air filter 56. An exhaust-gas introducing port 54-2 is connected to an exhaust pipe 23 through a path 58. The pressure of the fresh-air intake port 54-1 and the exhaust-gas introducing port 54-2 is higher than the pressure of the injecting port 53. Therefore, the atmosphere and the exhaust gas can be smoothly introduced into an air intake pipe 18.